Abstract
Mescaline, the primary bioactive alkaloid found in Peyote and San Pedro cactus, has been used in traditional medicine for centuries and is now attracting renewed interest for clinical applications. The purpose of this systematic review was to search the literature for studies reporting the use of mescaline to address the gap in our understanding of mescaline use and its impact. References were exported from PubMed, Scopus, Embase, and Cochrane. Included studies contained patient data pertaining to mescaline, primary sources for beliefs on the use of mescaline as traditional medicine, and a range of psychiatric conditions. Excluded studies included unpublished studies, animal studies, and studies without English full-texts available. Of 2770 imported references, 66 met the inclusion criteria, with only 10 being found suitable for analysis. Studies reported therapeutic effects such as improvements in depression scales, well-being, nicotine dependence, alcohol use, and obsessions. Bayesian analysis found that certain effects were frequently reported, such as hypertension, headache, nausea, and vomiting. The existing literature on mescaline is limited and of highly variable quality, preventing definitive conclusions regarding the prevalence of psychological and somatic effects from mescaline and mescaline-containing ethnobotanicals. Additional research is needed to determine the safety profile of mescaline. Given the prevalence of Peyote use in the Native American Church, the collaboration of the Native American Church and regional hospitals/poison centers is recommended to create a registry to allow for standardized and clinically applicable data collection on the effects of mescaline in prevalent populations.